White (Sweet) Miso

Miso is an umami-rich paste made by mixing beans (historically, soybeans), salt, and koji, a grain (usually rice) which has been inoculated and fermented with a mold, Aspergillus oryzae. The flavor and complexity of miso is unmatched even compared to other fermented dishes. It is at once savory, sweet, salty, and powerful.

White miso is lighter and sweeter than its more popular and traditional cousin, red miso (akamiso). That’s due to its shorter fermentation time (weeks instead of months or years), and higher ratio of koji (which is carbohydrate-rich and produces a sweeter finished product). Many modern commercial white misos are “cooked” rather than fermented, creating a finished product in a matter of days, not weeks.

Aspergillus oryzae under microscope

The easiest way to make miso is to start with pre-made dried koji. Local Asian markets usually carry dried “firm granular” koji. You can also find online merchants like this one.

Learn more about making your own koji here.

The making of miso…


White (shiro) Miso

Prep Time 12 hours
Fermentation Time 48 days
Cuisine Japanese
Makes 1 quarts/liters


  • food processor or high speed blender


  • 1 3/4 cups (300 g) dried beans (chickpea, adzuki, or other legume)
  • 2 1/2 cups (567 g) 1 tub, about 3.5 cups dried firm granular or 3 cups (650 g) fresh koji Here is more about koji
  • 5 tbsp (75 g) fine sea salt
  • 1 tbsp mature miso


Prepare Mixture

  • Soak the beans in 10 cups (2.5 liters) of filtered water overnight (or up to 24 hours).
  • Drain the beans well.
  • Bring 1/2 gallon (2 liters) of filtered water to a boil, then add beans and reduce heat to simmer. Cook until soft, about 30 to 60 minutes (exact cooking time varies by bean).
  • Save the bean cooking liquid. Place a colander over another pot, mixing bowl or other heat-proof container, then use it to drain the beans and capture their cooking liquid. Place the drained beans in a large mixing bowl or put them back in the cooking pot once it has cooled down.
  • Let the cooking liquid mixture cool down to 100°F / 38°C.
  • Mash the beans, leaving about 1/4 of them intact.
  • Reserve 1/2 tsp (3 g) of salt for later, and stir the rest of the salt into the bean mixture.
  • Add the mature miso to the beans. Stir until it’s well incorporated.
  • Stir the koji into the bean mixture.
  • Once the cooking liquid has cooled down, add 2 1/4 cups (540 ml) of liquid to the mixture if using dried koji, or 1 1/3 cups (310 ml) liquid if using fresh koji.
  • Mix well for 5 minutes in order to allow the koji to absorb the cooking liquid.
  • Once the miso is well mixed, you should be able to form it into balls that hold together without any liquid coming out when you gently squeeze them. If the miso crumbles in your hand, add more cooking liquid to the mixture, stir well, and then try the squeeze test again.


  • Pack the vessel with the miso mixture, ensuring that there are no air bubbles as you go. Leave 1 inch (2.5 cm) of room between the mixture and the top of the vessel.
  • Tap the vessel it on a folded towel or wooden cutting board several times to remove any air pockets. Make sure the top surface is even and flat.
  • Add a layer of salt to the top.
  • Add a weight (fermentation weights, a plate, etc.) to the top of the mixture. This will press the miso down and allow the tamari to rise to the surface during fermentation.
  • Set the vessel on a plate or in a shallow food storage container.
  • Affix a label to the side of your vessel with the current date.
  • Store the miso at warm room temperature (ideally between 72 and 80°F / 22 and 27°C) for 4 to 8 weeks.

Post Fermentation

  • Remove the lid and weights. Scoop off any funky mold from the top surface of the miso.
  • Blend the miso into a smooth paste using a food processor or high-speed blender. Add a small amount of filtered water if mixture is too thick to blend.
  • Pack the miso into glass jars. If you’re using a metal lid, place a layer of parchment or wax paper between the metal lid and the lip of the jar before you secure the jar.
  • Store the miso in the refrigerator, where it will last for several months.


After miso has been fermented, I like to blend it into a smooth paste. It is easier to incorporate it into dishes as a paste than when it is chunky.


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